1. Field of the Invention
Food preparation devices are known which permit a random selection of the introduction and removal of products contained in boxes, baskets, and other containers for the purposes of cooking and cooling. The introduction and removal of products into and out of these devices are effected by a single robot or automation, making these movements one after the other.
2. Discussion of Background and Relevant Information
For other food preparation devices, the cooking and refrigeration occur in tunnel, where introduction and removal can only be done consecutively, one after another. The principal drawback of these devices is that they do not permit the mixing of products having different treatment times. The products must be treated by cooking family, one after the other. Because, the boxes of products follow each other, they must be removed one after the other. Because of this drawback certain products are either overcooked, or over-refrigerated where an excess of cold destroys all taste quality. In these devices, the loading and unloading of the food containers are performed by a single robot, the operations are slower, and require some waiting.
U.S. Pat. No. 3,821,925 describes a cooking device with introduction and removal of baskets containing the products to be treated. The device is composed of two parts: a lower part, and a cover overlapping this lower part serving to treat the products with heat, the cover being movable to permit the removal and introduction of a basket integrated with said cover and containing the products to be treated. This device, conceived for frying under pressure, does not permit different cooking or cooling times in the same chamber and does not lend itself to the automatization of the introduction and removal operations of the products to be treated.
French Patent Document No. 2,596,250 describes a device intended for cooking alimentary doughs. It includes a cooking container and several sintering boxes receiving the baskets containing the doughs to be cooked. The movement and the length of time for the immersion of each sintering box is automatically controlled. This apparatus has no cover, which does not permit the evacuation of cooking gases leading to mediocre thermal efficiency.
The device described below avoids all of these drawbacks. It consists of two parts: a lower part receiving the products to be treated, and an upper part overhanging the lower part serving as a hood and a cover for it.
For the cooking device, the lower part consists of a vat, or several vats side-by-side. Several types of cooking can be performed: flowing vapor, superheated vapor, pulsating air, slow heat, water immersion, and also cooking in oil, like deep frying.
Several devices can be added in modules, one after the other, and each module has its cover equipped with an autonomous introduction and removal system. This system, for reasons of economy, can be the same for all of the modules.
To permit the introduction and removal of products to be cooked or cooled, the raising and lowering system lifts up the hood-cover with the help of an endless screw, by a chain controlled by an electric drive, by a winder, or by any other method attached to a ramp. The hood-cover is integrated with the raising and lowering system, and in a raised position, it permits the detachment of the hot or cold treatment vat, as well as allowing the introduction and removal of baskets containing the products. These baskets are introduced or removed by a robot arm sliding on an endless transverse screw attached under the hood-cover, raising and lowering with it.
The transverse endless screw allows the introduction of the baskets into the vat, or their removal onto an external conveyor. Several arms motorized and controlled by an exterior console, can exist alongside each other according to the number of vats.
In the vat where the products finish their treatment, the fork of the arm grasps the basket, and the hood-cover goes up, letting the basket be removed outside by the arm sliding on its endless screw. Only the robot arm which receives the command by a switch located on its fork, grasps the basket and removes it. The baskets are not grasped will remain in the finishing end treatment area. To introduce the baskets, a switch placed on the conveyor signals the hood-cover raise, and to the robot arm to seize the basket. Without the basket, the robot arm cannot function.
At the end of the operation a switch on the endless screw of the robot arm will center the basket in the vat. Just as for the raising and lowering of the hood-cover, a control cam controls the opening and closing function of the hood-cover.
In order to permit easy passage of the carrier arm with its fork, taking or putting the basket on the conveyor or even from a cart at a constant level, a guillotine or tilting door, motorized or not, opens simultaneously as the carrier robot arm advances. The conveyor bringing or removing the baskets may or may not be used depending on what is needed.
During the raising of the cover, the skirt slides along the entire periphery of the device to prevent the loss of heat or cold.
A programmable automation controls, activates, or stops all the operations.
Above the guillotine door and the conveyor, a filtering hood evacuates the vapors at the moment the products exit. This hood is attached to a supple conduit and is flexible up to the rear extraction sheath evacuating the cooking vapors.
Using the device with flowing vapor, a control key controls the evacuation of vapors because these are not modulated, they accumulate in the induction hood and are not sufficient to cook the products. For refrigeration purposes extraction sheaths are not necessary.
An air of water condenser allows the recovery of all condensation. An induction ventilator can be provided to evacuate the steam or oil vapors. The condensation waters can be evacuated by an external evacuation, or they can be recycled into the water of the cooking vat, thereby conserving water.
Under the hood-cover, electric super heaters and a turbine superheat the flowing vapors or are used for pulsating air or for dry vapor. The temperature of the super heaters can surpass 120.degree. in order to destroy bacteria and salmonella, which are not destroyed by the simple flowing vapor which is limited to about 99.degree.. This temperature is insufficient to destroy certain bacteria.
For cooking with pulsating air only the super heaters are used, and a turbine serves to agitate this hot air with an induction and output direction.
On the periphery of the hood-cover, and on the periphery of the vat receiving the cover, a joint on each of the two parts permits them to close hermetically, in order to prevent vapors, the heat and the cold from the cooling device from escaping.
For water immersion cooking, a pump recycles the water in the vat to eliminate the amydons and starches, and to remove them at an overflow level A when the vat is too full with water. With flowing vapor, another overflow level B evacuates the excess water, an electrovalve regulates and controls the water level. A general faucet permits the closed vat to be emptied by a valve when cooking by water immersion.
A grease collector located at the exit of the two overflow levels recovers the greases.
Two switches i.e., upper and lower switches determine the overflow levels chosen by the operator.
The cooking vat is heated either by gas or electric burners placed in it.
The same device will be used for cold bonding, that is, very rapid cooling of hot products before their temperature descends below 65.degree., in order to respect the law, to prevent the growth of bacteria. The device has the same introduction and removal system as the hot one. Refrigeration is assured by a cold compressor, CO.sub.2, or liquid nitrogen, with an adequate ventilator distributing the cold evenly in the device. The device can be coupled to the hot one with the same introduction and removal conveyor for the baskets.
Between the two devices, a salamander grill permits the operating agents to sprinkle, decorate, and prepare, the food before the products are introduced into the cold area.
A programmable automation permits, in the cooling device the determination of the cooling time necessary for each product. These products must be cooled in less than two hours according to the law, and the compressor and evaporators must be designed with this in mind.
The cooling device, having products with different treatment times, raises and lowers, and the robot arm effects their operation as in the cooking device.
Each product must be immediately removed after its cooling time has elapsed, in order to preserve all of the taste and aesthetic qualities of the products which are otherwise destroyed by prolonged cold ventilation.
A continuous production line can be envisaged with the cooking and cooling modules following each other in order to effect a coherent operation.
A general programmable automation operates the whole production line.
This device allows the cooking and cooling of products, which have been prepackaged raw and vacuum packed in plastic pouches, with the cooking being done by vapor plus pulsating air. Prepackaged raw products in covered cardboard or aluminum containers can also be treated, these products belonging to the semi-conserved cooking method which is often used in air pulsating ovens, but whose introduction and removal is done manually. When a single product is being cooked or cooled, a single treatment time can be used, contrary to the device which was just described.